This chapter is from the book

This chapter is from the book

What the BIOS Is and What It Does

The ROM (read only memory) BIOS (basic input/output system) chip on the
computer's motherboard is designed to provide the essential interfacing
between hardware (such as drives, the clock, the CPU, the chipset, ports, and
video) and software (the operating system). Although video, some SCSI, and a few
IDE add-on cards might also have BIOS chips that help manage those devices,
whenever we refer to the computer's BIOS chip, we mean the one on the
motherboard. The BIOS chip is often referred to as the ROM BIOS because, in its
traditional form, it was a read-only memory chip with contents that could not be
changed. Later versions could be reprogrammed with an EPROM programmer, and,
beginning in the mid-1990s, BIOSes using flash memory (flash BIOS) began to
appear. Flash BIOSes can be reprogrammed through software, and virtually all
BIOSes on Pentium-class machines and beyond are flash-upgradeable.

Regardless of its form, the BIOS chip on the motherboard is also known as the
system BIOS.